moebius#226: Consider blocking top level window data: URIs (part 2/2 without tests)

https://github.com/MoonchildProductions/moebius/pull/226

16 files changed, 194 insertions, 66 deletions

diff --git a/docshell/base/nsDSURIContentListener.cpp b/docshell/base/nsDSURIContentListener.cpp
index 93ce3cb264..ee6a4dd623 100644
--- a/docshell/base/nsDSURIContentListener.cpp
+++ b/docshell/base/nsDSURIContentListener.cpp
@@ -17,6 +17,7 @@
 #include "nsIHttpChannel.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsError.h"
+#include "nsContentSecurityManager.h"
 #include "nsCharSeparatedTokenizer.h"
 #include "nsIConsoleService.h"
 #include "nsIScriptError.h"
@@ -93,6 +94,14 @@ nsDSURIContentListener::DoContent(const nsACString& aContentType,
 
   if (aOpenedChannel) {
     aOpenedChannel->GetLoadFlags(&loadFlags);
+
+    // block top-level data URI navigations if triggered by the web
+    if (!nsContentSecurityManager::AllowTopLevelNavigationToDataURI(aOpenedChannel)) {
+      // logging to console happens within AllowTopLevelNavigationToDataURI
+      aRequest->Cancel(NS_ERROR_DOM_BAD_URI);
+      *aAbortProcess = true;
+      return NS_OK; 
+    }
   }
 
   if (loadFlags & nsIChannel::LOAD_RETARGETED_DOCUMENT_URI) {
diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index ae97a7c9e3..596bd5d848 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -9885,15 +9885,6 @@ nsDocShell::InternalLoad(nsIURI* aURI,
     contentType = nsIContentPolicy::TYPE_DOCUMENT;
   }
 
-  if (!nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
-        aURI,
-        contentType,
-        aTriggeringPrincipal,
-        (aLoadType == LOAD_NORMAL_EXTERNAL))) {
-    // logging to console happens within AllowTopLevelNavigationToDataURI
-    return NS_OK;
-  }
-
   // If there's no targetDocShell, that means we are about to create a new window,
   // perform a content policy check before creating the window.
   if (!targetDocShell) {
@@ -10962,6 +10953,7 @@ nsDocShell::DoURILoad(nsIURI* aURI,
   if (aPrincipalToInherit) {
     loadInfo->SetPrincipalToInherit(aPrincipalToInherit);
   }
+  loadInfo->SetLoadTriggeredFromExternal(aLoadFromExternal);
 
   // We have to do this in case our OriginAttributes are different from the
   // OriginAttributes of the parent document. Or in case there isn't a
diff --git a/dom/security/nsContentSecurityManager.cpp b/dom/security/nsContentSecurityManager.cpp
index 069e7d6a70..c987fed67b 100644
--- a/dom/security/nsContentSecurityManager.cpp
+++ b/dom/security/nsContentSecurityManager.cpp
@@ -10,20 +10,16 @@
 #include "nsIStreamListener.h"
 #include "nsIDocument.h"
 #include "nsMixedContentBlocker.h"
-#include "nsNullPrincipal.h"
 
 #include "mozilla/dom/Element.h"
+#include "mozilla/dom/TabChild.h"
 
 NS_IMPL_ISUPPORTS(nsContentSecurityManager,
                   nsIContentSecurityManager,
                   nsIChannelEventSink)
 
 /* static */ bool
-nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
-  nsIURI* aURI,
-  nsContentPolicyType aContentPolicyType,
-  nsIPrincipal* aTriggeringPrincipal,
-  bool aLoadFromExternal)
+nsContentSecurityManager::AllowTopLevelNavigationToDataURI(nsIChannel* aChannel)
 {
   // Let's block all toplevel document navigations to a data: URI.
   // In all cases where the toplevel document is navigated to a
@@ -36,17 +32,24 @@ nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
   if (!mozilla::net::nsIOService::BlockToplevelDataUriNavigations()) {
     return true;
   }
-  if (aContentPolicyType != nsIContentPolicy::TYPE_DOCUMENT) {
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
+  if (!loadInfo) {
+    return true;
+  }
+  if (loadInfo->GetExternalContentPolicyType() != nsIContentPolicy::TYPE_DOCUMENT) {
     return true;
   }
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
+  NS_ENSURE_SUCCESS(rv, true);
   bool isDataURI =
-    (NS_SUCCEEDED(aURI->SchemeIs("data", &isDataURI)) && isDataURI);
+    (NS_SUCCEEDED(uri->SchemeIs("data", &isDataURI)) && isDataURI);
   if (!isDataURI) {
     return true;
   }
   // Whitelist data: images as long as they are not SVGs
   nsAutoCString filePath;
-  aURI->GetFilePath(filePath);
+  uri->GetFilePath(filePath);
   if (StringBeginsWith(filePath, NS_LITERAL_CSTRING("image/")) &&
       !StringBeginsWith(filePath, NS_LITERAL_CSTRING("image/svg+xml"))) {
     return true;
@@ -56,22 +59,29 @@ nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
       StringBeginsWith(filePath, NS_LITERAL_CSTRING("application/json"))) {
     return true;
   }
-  if (!aLoadFromExternal &&
-      nsContentUtils::IsSystemPrincipal(aTriggeringPrincipal)) {
+  // Redirecting to a toplevel data: URI is not allowed, hence we make
+  // sure the RedirectChain is empty.
+  if (!loadInfo->GetLoadTriggeredFromExternal() &&
+      nsContentUtils::IsSystemPrincipal(loadInfo->TriggeringPrincipal()) &&
+      loadInfo->RedirectChain().IsEmpty()) {
     return true;
   }
   nsAutoCString dataSpec;
-  aURI->GetSpec(dataSpec);
+  uri->GetSpec(dataSpec);
   if (dataSpec.Length() > 50) {
     dataSpec.Truncate(50);
     dataSpec.AppendLiteral("...");
   }
+  nsCOMPtr<nsITabChild> tabChild = do_QueryInterface(loadInfo->ContextForTopLevelLoad());
+  nsCOMPtr<nsIDocument> doc;
+  if (tabChild) {
+    doc = static_cast<mozilla::dom::TabChild*>(tabChild.get())->GetDocument();
+  }
   NS_ConvertUTF8toUTF16 specUTF16(NS_UnescapeURL(dataSpec));
   const char16_t* params[] = { specUTF16.get() };
   nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                   NS_LITERAL_CSTRING("DATA_URI_BLOCKED"),
-                                  // no doc available, log to browser console
-                                  nullptr,
+                                  doc,
                                   nsContentUtils::eSECURITY_PROPERTIES,
                                   "BlockTopLevelDataURINavigation",
                                   params, ArrayLength(params));
@@ -541,27 +551,6 @@ nsContentSecurityManager::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
     }
   }
 
-  // Redirecting to a toplevel data: URI is not allowed, hence we pass
-  // a NullPrincipal as the TriggeringPrincipal to
-  // AllowTopLevelNavigationToDataURI() which definitely blocks any
-  // data: URI load.
-  nsCOMPtr<nsILoadInfo> newLoadInfo = aNewChannel->GetLoadInfo();
-  if (newLoadInfo) {
-    nsCOMPtr<nsIURI> uri;
-    nsresult rv = NS_GetFinalChannelURI(aNewChannel, getter_AddRefs(uri));
-    NS_ENSURE_SUCCESS(rv, rv);
-    nsCOMPtr<nsIPrincipal> nullTriggeringPrincipal = nsNullPrincipal::Create();
-    if (!nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
-          uri,
-          newLoadInfo->GetExternalContentPolicyType(),
-          nullTriggeringPrincipal,
-          false)) {
-        // logging to console happens within AllowTopLevelNavigationToDataURI
-      aOldChannel->Cancel(NS_ERROR_DOM_BAD_URI);
-      return NS_ERROR_DOM_BAD_URI;
-    }
-  }
-
   // Also verify that the redirecting server is allowed to redirect to the
   // given URI
   nsCOMPtr<nsIPrincipal> oldPrincipal;
diff --git a/dom/security/nsContentSecurityManager.h b/dom/security/nsContentSecurityManager.h
index 09b6c86aa1..bab8477434 100644
--- a/dom/security/nsContentSecurityManager.h
+++ b/dom/security/nsContentSecurityManager.h
@@ -32,10 +32,7 @@ public:
   static nsresult doContentSecurityCheck(nsIChannel* aChannel,
                                          nsCOMPtr<nsIStreamListener>& aInAndOutListener);
 
-  static bool AllowTopLevelNavigationToDataURI(nsIURI* aURI,
-                                               nsContentPolicyType aContentPolicyType,
-                                               nsIPrincipal* aTriggeringPrincipal,
-                                               bool aLoadFromExternal);
+  static bool AllowTopLevelNavigationToDataURI(nsIChannel* aChannel);
 
 private:
   static nsresult CheckChannel(nsIChannel* aChannel);
diff --git a/dom/security/test/general/browser.ini b/dom/security/test/general/browser.ini
index 97ddae3bf3..73ae72dddd 100644
--- a/dom/security/test/general/browser.ini
+++ b/dom/security/test/general/browser.ini
@@ -3,3 +3,9 @@
 support-files =
   file_toplevel_data_navigations.sjs
   file_toplevel_data_meta_redirect.html
+[browser_test_data_download.js]
+support-files =
+  file_data_download.html
+[browser_test_data_text_csv.js]
+support-files =
+  file_data_text_csv.html
diff --git a/dom/security/test/general/browser_test_data_download.js b/dom/security/test/general/browser_test_data_download.js
new file mode 100644
index 0000000000..1ee8d58449
--- /dev/null
+++ b/dom/security/test/general/browser_test_data_download.js
@@ -0,0 +1,37 @@
+"use strict";
+
+const kTestPath = getRootDirectory(gTestPath)
+                  .replace("chrome://mochitests/content", "http://example.com")
+const kTestURI = kTestPath + "file_data_download.html";
+
+function addWindowListener(aURL, aCallback) {
+  Services.wm.addListener({
+    onOpenWindow(aXULWindow) {
+      info("window opened, waiting for focus");
+      Services.wm.removeListener(this);
+      var domwindow = aXULWindow.QueryInterface(Ci.nsIInterfaceRequestor)
+                                .getInterface(Ci.nsIDOMWindow);
+      waitForFocus(function() {
+        is(domwindow.document.location.href, aURL, "should have seen the right window open");
+        aCallback(domwindow);
+      }, domwindow);
+    },
+    onCloseWindow(aXULWindow) { },
+    onWindowTitleChange(aXULWindow, aNewTitle) { }
+  });
+}
+
+function test() {
+  waitForExplicitFinish();
+  Services.prefs.setBoolPref("security.data_uri.block_toplevel_data_uri_navigations", true);
+  registerCleanupFunction(function() {
+    Services.prefs.clearUserPref("security.data_uri.block_toplevel_data_uri_navigations");
+  });
+  addWindowListener("chrome://mozapps/content/downloads/unknownContentType.xul", function(win) {
+    is(win.document.getElementById("location").value, "data-foo.html",
+       "file name of download should match");
+     win.close();
+     finish();
+  });
+  gBrowser.loadURI(kTestURI);
+}
diff --git a/dom/security/test/general/browser_test_data_text_csv.js b/dom/security/test/general/browser_test_data_text_csv.js
new file mode 100644
index 0000000000..c45e40cc2e
--- /dev/null
+++ b/dom/security/test/general/browser_test_data_text_csv.js
@@ -0,0 +1,37 @@
+"use strict";
+
+const kTestPath = getRootDirectory(gTestPath)
+                  .replace("chrome://mochitests/content", "http://example.com")
+const kTestURI = kTestPath + "file_data_text_csv.html";
+
+function addWindowListener(aURL, aCallback) {
+  Services.wm.addListener({
+    onOpenWindow(aXULWindow) {
+      info("window opened, waiting for focus");
+      Services.wm.removeListener(this);
+      var domwindow = aXULWindow.QueryInterface(Ci.nsIInterfaceRequestor)
+                                .getInterface(Ci.nsIDOMWindow);
+      waitForFocus(function() {
+        is(domwindow.document.location.href, aURL, "should have seen the right window open");
+        aCallback(domwindow);
+      }, domwindow);
+    },
+    onCloseWindow(aXULWindow) { },
+    onWindowTitleChange(aXULWindow, aNewTitle) { }
+  });
+}
+
+function test() {
+  waitForExplicitFinish();
+  Services.prefs.setBoolPref("security.data_uri.block_toplevel_data_uri_navigations", true);
+  registerCleanupFunction(function() {
+    Services.prefs.clearUserPref("security.data_uri.block_toplevel_data_uri_navigations");
+  });
+  addWindowListener("chrome://mozapps/content/downloads/unknownContentType.xul", function(win) {
+    is(win.document.getElementById("location").value, "text/csv;foo,bar,foobar",
+       "file name of download should match");
+     win.close();
+     finish();
+  });
+  gBrowser.loadURI(kTestURI);
+}
diff --git a/dom/security/test/general/file_data_download.html b/dom/security/test/general/file_data_download.html
new file mode 100644
index 0000000000..4cc92fe8f5
--- /dev/null
+++ b/dom/security/test/general/file_data_download.html
@@ -0,0 +1,14 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test download attribute for data: URI</title>
+</head>
+<body>
+  <a href="data:text/html,<body>data download</body>" download="data-foo.html" id="testlink">download data</a>
+  <script>
+    // click the link to have the downoad panel appear
+    let testlink = document.getElementById("testlink");
+    testlink.click();
+  </script>
+  </body>
+</html>
diff --git a/dom/security/test/general/file_data_text_csv.html b/dom/security/test/general/file_data_text_csv.html
new file mode 100644
index 0000000000..a9ac369d16
--- /dev/null
+++ b/dom/security/test/general/file_data_text_csv.html
@@ -0,0 +1,14 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test open data:text/csv</title>
+</head>
+<body>
+  <a href="data:text/csv;foo,bar,foobar" id="testlink">test text/csv</a>
+  <script>
+    // click the link to have the downoad panel appear
+    let testlink = document.getElementById("testlink");
+    testlink.click();
+  </script>
+  </body>
+</html>
diff --git a/dom/security/test/general/test_block_toplevel_data_img_navigation.html b/dom/security/test/general/test_block_toplevel_data_img_navigation.html
index 2b8f62760a..7f8dfc7480 100644
--- a/dom/security/test/general/test_block_toplevel_data_img_navigation.html
+++ b/dom/security/test/general/test_block_toplevel_data_img_navigation.html
@@ -34,15 +34,17 @@ function test_toplevel_data_image_svg() {
   const DATA_SVG =
     "data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxNiIgaGVpZ2h0PSIxNiIgdmlld0JveD0iMCAwIDE2IDE2Ij4KICA8cGF0aCBkPSJNOCwxMkwzLDcsNCw2bDQsNCw0LTQsMSwxWiIgZmlsbD0iIzZBNkE2QSIgLz4KPC9zdmc+Cg==";
   let win2 = window.open(DATA_SVG);
-  let wrappedWin2 = SpecialPowers.wrap(win2);
-  setTimeout(function () {
-    isnot(wrappedWin2.document.documentElement.localName, "svg",
-          "Loading data:image/svg+xml should be blocked");
-    wrappedWin2.close();
-    SimpleTest.finish();
-  }, 1000);
+  // Unfortunately we can't detect whether the window was closed using some event,
+  // hence we are constantly polling till we see that win == null.
+  // Test times out on failure.
+  var win2Closed = setInterval(function() {
+    if (win2 == null || win2.closed) {
+      clearInterval(win2Closed);
+      ok(true, "Loading data:image/svg+xml should be blocked");
+      SimpleTest.finish();
+    }
+  }, 200);
 }
-
 // fire up the tests
 test_toplevel_data_image();
 
diff --git a/dom/security/test/general/test_block_toplevel_data_navigation.html b/dom/security/test/general/test_block_toplevel_data_navigation.html
index fc91f2ec0a..cef232b65a 100644
--- a/dom/security/test/general/test_block_toplevel_data_navigation.html
+++ b/dom/security/test/general/test_block_toplevel_data_navigation.html
@@ -21,16 +21,12 @@ function test1() {
   // simple data: URI click navigation should be prevented
   let TEST_FILE = "file_block_toplevel_data_navigation.html";
   let win1 = window.open(TEST_FILE);
-  var readyStateCheckInterval = setInterval(function() {
-    let state = win1.document.readyState;
-    if (state === "interactive" || state === "complete") {
-      clearInterval(readyStateCheckInterval);
-      ok(win1.document.body.innerHTML.indexOf("test1:") !== -1,
-         "toplevel data: URI navigation through click() should be blocked");
-      win1.close();
-      test2();
-    }
-  }, 200);
+  setTimeout(function () {
+    ok(SpecialPowers.wrap(win1).document.body.innerHTML.indexOf("test1:") !== -1,
+      "toplevel data: URI navigation through click() should be blocked");
+    win1.close();
+    test2();
+  }, 1000);
 }
 
 function test2() {
diff --git a/ipc/glue/BackgroundUtils.cpp b/ipc/glue/BackgroundUtils.cpp
index b335f5c23d..4cfbe8758f 100644
--- a/ipc/glue/BackgroundUtils.cpp
+++ b/ipc/glue/BackgroundUtils.cpp
@@ -294,6 +294,7 @@ LoadInfoToLoadInfoArgs(nsILoadInfo *aLoadInfo,
       aLoadInfo->CorsUnsafeHeaders(),
       aLoadInfo->GetForcePreflight(),
       aLoadInfo->GetIsPreflight(),
+      aLoadInfo->GetLoadTriggeredFromExternal(),
       aLoadInfo->GetForceHSTSPriming(),
       aLoadInfo->GetMixedContentWouldBlock());
 
@@ -370,6 +371,7 @@ LoadInfoArgsToLoadInfo(const OptionalLoadInfoArgs& aOptionalLoadInfoArgs,
                           loadInfoArgs.corsUnsafeHeaders(),
                           loadInfoArgs.forcePreflight(),
                           loadInfoArgs.isPreflight(),
+                          loadInfoArgs.loadTriggeredFromExternal(),
                           loadInfoArgs.forceHSTSPriming(),
                           loadInfoArgs.mixedContentWouldBlock()
                           );
diff --git a/netwerk/base/LoadInfo.cpp b/netwerk/base/LoadInfo.cpp
index 42fdea4a18..2f10261cb3 100644
--- a/netwerk/base/LoadInfo.cpp
+++ b/netwerk/base/LoadInfo.cpp
@@ -7,6 +7,7 @@
 #include "mozilla/LoadInfo.h"
 
 #include "mozilla/Assertions.h"
+#include "mozilla/dom/TabChild.h"
 #include "mozilla/dom/ToJSValue.h"
 #include "mozIThirdPartyUtil.h"
 #include "nsFrameLoader.h"
@@ -63,6 +64,7 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadingPrincipal,
   , mIsThirdPartyContext(false)
   , mForcePreflight(false)
   , mIsPreflight(false)
+  , mLoadTriggeredFromExternal(false)
   , mForceHSTSPriming(false)
   , mMixedContentWouldBlock(false)
 {
@@ -235,6 +237,7 @@ LoadInfo::LoadInfo(nsPIDOMWindowOuter* aOuterWindow,
   , mIsThirdPartyContext(false) // NB: TYPE_DOCUMENT implies not third-party.
   , mForcePreflight(false)
   , mIsPreflight(false)
+  , mLoadTriggeredFromExternal(false)
   , mForceHSTSPriming(false)
   , mMixedContentWouldBlock(false)
 {
@@ -297,6 +300,7 @@ LoadInfo::LoadInfo(const LoadInfo& rhs)
   , mCorsUnsafeHeaders(rhs.mCorsUnsafeHeaders)
   , mForcePreflight(rhs.mForcePreflight)
   , mIsPreflight(rhs.mIsPreflight)
+  , mLoadTriggeredFromExternal(rhs.mLoadTriggeredFromExternal)
   , mForceHSTSPriming(rhs.mForceHSTSPriming)
   , mMixedContentWouldBlock(rhs.mMixedContentWouldBlock)
 {
@@ -325,6 +329,7 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadingPrincipal,
                    const nsTArray<nsCString>& aCorsUnsafeHeaders,
                    bool aForcePreflight,
                    bool aIsPreflight,
+                   bool aLoadTriggeredFromExternal,
                    bool aForceHSTSPriming,
                    bool aMixedContentWouldBlock)
   : mLoadingPrincipal(aLoadingPrincipal)
@@ -348,6 +353,7 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadingPrincipal,
   , mCorsUnsafeHeaders(aCorsUnsafeHeaders)
   , mForcePreflight(aForcePreflight)
   , mIsPreflight(aIsPreflight)
+  , mLoadTriggeredFromExternal(aLoadTriggeredFromExternal)
   , mForceHSTSPriming (aForceHSTSPriming)
   , mMixedContentWouldBlock(aMixedContentWouldBlock)
 {
@@ -873,6 +879,23 @@ LoadInfo::GetIsPreflight(bool* aIsPreflight)
 }
 
 NS_IMETHODIMP
+LoadInfo::SetLoadTriggeredFromExternal(bool aLoadTriggeredFromExternal)
+{
+  MOZ_ASSERT(!aLoadTriggeredFromExternal ||
+             mInternalContentPolicyType == nsIContentPolicy::TYPE_DOCUMENT,
+             "can only set load triggered from external for TYPE_DOCUMENT");
+  mLoadTriggeredFromExternal = aLoadTriggeredFromExternal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+LoadInfo::GetLoadTriggeredFromExternal(bool* aLoadTriggeredFromExternal)
+{
+  *aLoadTriggeredFromExternal = mLoadTriggeredFromExternal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
 LoadInfo::GetForceHSTSPriming(bool* aForceHSTSPriming)
 {
   *aForceHSTSPriming = mForceHSTSPriming;
diff --git a/netwerk/base/LoadInfo.h b/netwerk/base/LoadInfo.h
index 3e1b92ff4c..99deae2d25 100644
--- a/netwerk/base/LoadInfo.h
+++ b/netwerk/base/LoadInfo.h
@@ -108,6 +108,7 @@ private:
            const nsTArray<nsCString>& aUnsafeHeaders,
            bool aForcePreflight,
            bool aIsPreflight,
+           bool aLoadTriggeredFromExternal,
            bool aForceHSTSPriming,
            bool aMixedContentWouldBlock);
   LoadInfo(const LoadInfo& rhs);
@@ -152,6 +153,7 @@ private:
   nsTArray<nsCString>              mCorsUnsafeHeaders;
   bool                             mForcePreflight;
   bool                             mIsPreflight;
+  bool                             mLoadTriggeredFromExternal;
 
   bool                             mForceHSTSPriming : 1;
   bool                             mMixedContentWouldBlock : 1;
diff --git a/netwerk/base/nsILoadInfo.idl b/netwerk/base/nsILoadInfo.idl
index 78433c8b88..5b5eb425a6 100644
--- a/netwerk/base/nsILoadInfo.idl
+++ b/netwerk/base/nsILoadInfo.idl
@@ -575,6 +575,13 @@ interface nsILoadInfo : nsISupports
   [infallible] attribute boolean initialSecurityCheckDone;
 
   /**
+   * Returns true if the load was triggered from an external application
+   * (e.g. Thunderbird). Please note that this flag will only ever be true
+   * if the load is of TYPE_DOCUMENT. 
+   */
+  [infallible] attribute boolean loadTriggeredFromExternal;
+
+  /**
    * Whenever a channel gets redirected, append the principal of the
    * channel [before the channels got redirected] to the loadinfo,
    * so that at every point this array lets us reason about all the
diff --git a/netwerk/ipc/NeckoChannelParams.ipdlh b/netwerk/ipc/NeckoChannelParams.ipdlh
index 9365397d19..e1438caccb 100644
--- a/netwerk/ipc/NeckoChannelParams.ipdlh
+++ b/netwerk/ipc/NeckoChannelParams.ipdlh
@@ -53,6 +53,7 @@ struct LoadInfoArgs
   nsCString[]           corsUnsafeHeaders;
   bool                  forcePreflight;
   bool                  isPreflight;
+  bool                  loadTriggeredFromExternal;
   bool                  forceHSTSPriming;
   bool                  mixedContentWouldBlock;
 };